1Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS/ Univ. Paris 12 et 7, Créteil, France
2Institut für Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Germany
3UPMC Univ Paris 06, CNRS UMR8190, LATMOS/IPSL, Paris, France
4Laboratoire de Physique Moléculaire pour l'Atmosphére et l'Astrophysique, Université Pierre et Marie Curie-Paris 6, Paris, France
5Spectroscopie de l'Atmosphère, Service de Chimie Quantique et de Photophysique, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium
6Meteorological Observatory Hohenpeißenberg, DWD, Hohenpeißenberg, Germany
7Richard-Aßmann-Observatorium, DWD, Lindenberg, Germany
8NOAA/ESRL, Boulder, CO, USA
9Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
10Finnish Meteorological Institute, Sodankylä, Finland
11Ozone Layer Monitoring Office, Japan Meteorological Agency, Tokyo, 100-8122 Japan
12Agencia Estatal de Meteorología (AEMET), Madrid, Spain
13Met Éireann, The Irish Meteorological Service, Valentia Observatory, Cahirciveen, Kerry, Ireland
14Met Office, Exeter, UK
15NASA Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, USA
16Federal Office of Meteorology and Climatology, MeteoSwiss, Aerological Station, Payerne, Switzerland
*now at: Astrium GmbH, Germany
Received: 24 Feb 2009 – Discussion started: 08 May 2009
Abstract. This paper presents a first statistical validation of tropospheric ozone products derived from measurements of the IASI satellite instrument. Since the end of 2006, IASI (Infrared Atmospheric Sounding Interferometer) aboard the polar orbiter Metop-A measures infrared spectra of the Earth's atmosphere in nadir geometry. This validation covers the northern mid-latitudes and the period from July 2007 to August 2008. Retrieval results from four different sources are presented: three are from scientific products (LATMOS, LISA, LPMAA) and the fourth one is the pre-operational product distributed by EUMETSAT (version 4.2). The different products are derived from different algorithms with different approaches. The difference and their implications for the retrieved products are discussed. In order to evaluate the quality and the performance of each product, comparisons with the vertical ozone concentration profiles measured by balloon sondes are performed and lead to estimates of the systematic and random errors in the IASI ozone products (profiles and partial columns). A first comparison is performed on the given profiles; a second comparison takes into account the altitude dependent sensitivity of the retrievals. Tropospheric columnar amounts are compared to the sonde for a lower tropospheric column (surface to about 6 km) and a "total" tropospheric column (surface to about 11 km). On average both tropospheric columns have small biases for the scientific products, less than 2 Dobson Units (DU) for the lower troposphere and less than 1 DU for the total troposphere. The comparison of the still pre-operational EUMETSAT columns shows higher mean differences of about 5 DU.
Revised: 06 Nov 2009 – Accepted: 26 Nov 2009 – Published: 15 Dec 2009
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Keim, C., Eremenko, M., Orphal, J., Dufour, G., Flaud, J.-M., Höpfner, M., Boynard, A., Clerbaux, C., Payan, S., Coheur, P.-F., Hurtmans, D., Claude, H., Dier, H., Johnson, B., Kelder, H., Kivi, R., Koide, T., López Bartolomé, M., Lambkin, K., Moore, D., Schmidlin, F. J., and Stübi, R.: Tropospheric ozone from IASI: comparison of different inversion algorithms and validation with ozone sondes in the northern middle latitudes, Atmos. Chem. Phys., 9, 9329-9347, doi:10.5194/acp-9-9329-2009, 2009.